by Carolina Jemsby and David Bartal, Special for USA TODAY

by Carolina Jemsby and David Bartal, Special for USA TODAY

STOCKHOLM - Suburbs of the Swedish capital were engulfed in a fourth night of rioting early Thursday in the country's worst civil unrest in years, leaving locals shaking their heads and wondering when calm would return to their usually tranquil city.

Since Sunday, hundreds of young residents of the suburbs of Husby, Jakobsberg, Hagsatra, Skarholmenset and others set dozens of cars on fire, damaged buildings - including schools and a police station - and battled with police. There were about 10 arrests, and one police officer was reported injured.

Police spokesman Kjell Lindgren says at least 30 cars were set ablaze across western and southern Stockholm early Thursday. Firefighters said they have "never before seen so many fires raging at the same time."

Fire also destroyed a restaurant in Skogas, south of Stockholm.

Government officials have called for calm while the rioters say they won't stop until there is a full investigation into the shooting death of a 69-year-old mentally ill Husby man last week who, police say, was swinging a machete as police attempted a house search.

"Everyone must work to restore calm," said Prime Minister Fredrik Reinfeldt.

On Wednesday night and into Thursday, hundreds of residents walked the streets to answer the appeal for calm.

The unrest in poor, immigrant suburbs is only the latest to break out in Europe over the past decade following riots in Paris in 2005 and in London in 2011. But it has shocked both locals and those outside the rich northern country famous for its tolerance and generous welfare system known as the 'Swedish model,' a country also synonymous for its commitment to societal equality and justice.

Now, locals are wondering if Sweden has done any better than its European neighbors in assimilating its immigrant population, especially as administrations in the past two decades have been slowly dismantling the cradle-to-grave welfare benefits. That has led to rising income inequality that has hit the young and immigrants the hardest with unemployment running at 7% for the general population, and 16% among residents of foreign origin.

"In segregated areas, many are disappointed about their future prospects," said Eva Andersson, co-author of Segregation and Urban Unrest in Sweden, a new study by the universities of Stockholm and Uppsala. "You don't perceive the society as supportive, rather the opposite."

Stockholm is one of the world's richest cities, but it is also very segregated. In the suburbs engulfed in the rioting, most of the residents are of non-Swedish origin, mainly from Iraq, Iran, Turkey and Somalia.

Sweden has been traditionally welcoming of refugees and 15% of residents in the country are foreign-born, one of the highest ratios in Europe. But over the past two decades, Swedes have been increasingly worried over immigrants failing to integrate and the cost to the state in benefits. This concern has spurred the success of the anti-immigrant far right party, the Sweden Democrats, which won enough votes to enter Parliament for the first time in 2010 and is polling in third place in the run up to elections next year.

Meanwhile, some foreign-born residents of the riot-torn areas said they were angry at the rioters.

"It's idiotic ‚?? they're ruining things for the people that live here," Husby resident Marianne Farede, 26, who was born in Lebanon told the Swedish news website, The Local. "We're the ones that suffer. It's our cars that are getting burned; it's our money."

She said young people are using the incident as an excuse to cause trouble and said instead the youth should realize how good they have it.

"If I lived in my homeland, I wouldn't have it as good as I have it now," she added. "There aren't enough who do appreciate what they have ‚?? they want even more. You don't have to feel like a Swede to adjust to Swedish society."

Meanwhile, police say the riots are not spontaneous.

"It's obvious that there are organizations or a network who are using Facebook or other social media to call on people to go out and cause trouble," police spokesman Kjell Lindgren told national Swedish Radio, SR.

Swedish police added they are continuing to investigate the shooting incident.

Police officer Bert Jonsson noted that this is not the first time there have been disturbances in the Stockholm suburbs of Husby, Rinkeby and Tensta where most people are immigrants and unemployment is especially high.

"Some of the rioters claim that this time it is linked to the (police shooting) death a few nights ago of an elderly man here in Husby, but I don't know if that is the real reason," he said.

Late Wednesday afternoon, various Swedish citizens' groups held meetings to discuss the violence in the suburbs, that's been taking place during the last three nights.

In Husby, the run-down suburb northwest of Stockholm where the violence started late Sunday night, the "The Future of J√§rva" organization, as the greater area around Husby is called, complained of police violence, racism and governmental neglect of the suburbs.

"To disappoint Husby is to disappoint all suburbs in Sweden," said one speaker, writer and area resident Kurdo Baksi

But as he complained of the lack of government representatives from these districts to vigorous applause, someone through a stone into the group, hitting one man in his head.

Some locals said there was no cause for violence no matter how dire the situation of the young.

Cleo Peters from Grenada, visiting his adult daughter in Husby this week, said many young people in the Swedish projects have a poor education, little chance to land a decent job and have poor prospects for the future.

"They are like a lost generation," he said. But if he had a child out there rioting, he added, "I would punish him. In my country, they would get a whacking they wouldn't forget about."